System and device for exporting power, and method of configuring thereof

Abstract

System, device and method for exporting power are provided including at least one AC optimizer with plurality of DC inputs each connecting with respective one of plurality of DC sources, and independent maximum power point tracking (MPPT) performed for each respective DC source to extract power from each DC source for output and coupling to AC grid. When multiple AC optimizers are employed, with each AC optimizer having multiple DC inputs, each DC input can be connected to PV module with independent MPPT function. Since, each AC optimizer can serve multiple PV modules, significant cost saving and efficiencies can be achieved. Optionally, on PV sub-module level, each of the multiple DC inputs can be used as an independent MPPT channel for a PV sub-module cell string.

What is claimed is: 
     
       1. A system comprising:
 a plurality of inverting devices connected in series, wherein each of the plurality of inverting devices is configured to be connected with a plurality of power sources, and wherein at least one of the plurality of inverting devices comprises a plurality of dc/dc converters comprising a plurality of buck converter blocks and a shared output filter; and 
 a system controller having inputs connected to the plurality of inverting devices, and outputs configured to be connected to a power grid, wherein the system controller comprises a plurality of switches. 
 
     
     
       2. The system of  claim 1 , wherein:
 each of the plurality of inverting devices is configured to perform independent maximum power point tracking (MPPT) for a corresponding power source of the plurality of power sources. 
 
     
     
       3. The system of  claim 1 , wherein:
 at least one of the plurality of power sources is a photovoltaic (PV) module. 
 
     
     
       4. The system of  claim 1 , wherein:
 at least one of the plurality of power sources is a PV sub-module cell string. 
 
     
     
       5. The system of  claim 1 , wherein the at least one of the plurality of inverting devices comprises:
 the plurality of dc/dc converters connected in series, wherein each of the plurality of dc/dc converters is connected to a corresponding power source; and 
 an inverter having inputs connected to outputs of the plurality of dc/dc converters connected in series. 
 
     
     
       6. The system of  claim 5 , wherein:
 each of the plurality of buck converter blocks comprises two switches connected in series; and 
 the shared output filter is connected to a common node of the two switches. 
 
     
     
       7. A system comprising:
 a plurality of inverting devices connected in series, wherein each of the plurality of inverting devices is configured to be connected with a plurality of power sources, and wherein at least one of the plurality of inverting devices comprises a plurality of dc/dc converters comprising a plurality of buck converter blocks and a shared output filter; and 
 a system controller having inputs connected to the plurality of inverting devices, and outputs configured to be connected to a power grid. 
 
     
     
       8. The system of  claim 7 , wherein:
 the system controller comprises a plurality of switches. 
 
     
     
       9. The system of  claim 7 , wherein:
 the shared output filter is connected to a common node of the two switches of one of the plurality of buck converter blocks. 
 
     
     
       10. The system of  claim 7 , wherein:
 one of the plurality of inverting devices comprises a full-bridge inverter. 
 
     
     
       11. An inverter system comprising:
 a plurality of inverting devices connected in series, wherein each of the plurality of inverting devices is configured to be connected with a plurality of power sources, and at least one of the plurality of inverting devices comprises:
 a plurality of dc/dc converters, each of which is connected to a corresponding power source; 
 an inverter having inputs connected to outputs of the plurality of dc/dc converters; and 
 a shared output filter shared by the plurality of dc/dc converters; and 
 
 a system controller having inputs connected to the plurality of inverting devices, and outputs configured to be connected to a power grid. 
 
     
     
       12. The inverter system of  claim 11 , wherein:
 the system controller comprises a plurality of switches configured to control power flowing from the plurality of inverting devices and the power grid. 
 
     
     
       13. The inverter system of  claim 11 , wherein:
 the plurality of power sources, the plurality of dc/dc converters and the inverter are connected in cascade. 
 
     
     
       14. The inverter system of  claim 13 , wherein:
 one power source of the plurality of power sources is a PV module; 
 one dc/dc converter of the plurality of dc/dc converters is a non-isolated converter; and 
 the inverter is a full-bridge inverter. 
 
     
     
       15. The inverter system of  claim 11 , wherein:
 the shared output filter is an LC filter.